1. Soak 24 small skewers in water for 30 minutes. Preheat broiler to high; line a broiling pan with foil. Place beef, mushrooms and tomatoes in a large bowl. Add canola oil, salt and pepper and toss to coat.
2. Thread meat and vegetables onto skewers, alternating. Lay skewers on pan with handle ends facing out. Cover handle end with foil to prevent burning.
3. In a small bowl, mix sugar, soy sauce and sesame oil, stirring until sugar has dissolved. Broil skewers, turning a few times, until meat begins to brown, about 3 minutes. Brush liberally with glaze and continue broiling until beef is lightly charred, 2 to 3 minutes longer. Transfer to a platter and sprinkle with sesame seeds. Serve at room temperature.
Note: Nutritional analysis is per skewer.